Mercedes-Benz 2015 GLK Operator's Manual page 169

residues crystallize after time and contam-
inate the affected surfaces.
! DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to
the fuel tank, this can lead to engine dam-
age.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
The DEF filler neck is under the cargo com-
partment floor.
Switch the ignition off.
X
Open the tailgate.
X
Lift up the cargo compartment floor
X
( page 314).
Y
Turn DEF cap : counter-clockwise and
X
remove it.
Turn DEF filler cap ; counter-clockwise
X
and open it.
Filler cap ; is secured with a plastic strip.
Unscrew the protective cap from DEF refill
X
bottle =.
Set DEF refill bottle = as shown on the
X
filler neck and screw it on hand-tight.
Press DEF refill bottle = downward.
X
The DEF tank is filled. This may take up to
one minute.
i To top up between service intervals, fill
the DEF tank with approximately 1 gal
(3.8 l) of DEF. 1 gal (3.8 l) DEF is equivalent
to approximately 2 DEF refill bottles. Then
have the DEF supply checked at a qualified
specialist workshop and completely refilled
if necessary.
Release DEF refill bottle =.
X
When DEF refill bottle = is no longer
pressed down, filling stops. DEF refill bottle
= can be removed when it has been only
partially emptied.
Turn DEF refill bottle = counter-clockwise
X
and remove it.
Place DEF filler cap ; on the filler neck and
X
turn it clockwise.
Refueling
167
Z